1. Field of Invention
The present invention relates to systems, methods and apparatus relating to handling and processing of glass, such as for use in a liquid crystal display (LCD), and in particular to a LCD glass handling and processing system.
2. Description of Related Art
Producing flat product glass for LCD displays involves many challenges. A key requirement in this process is the ability to measure characteristics of the product glass, such as product distortion due to internal stresses in large product glass plates. Some large product glass plates range in size up to 3.2 meters square. Optical methods and gauging techniques have developed over the past several years to enable distortion measurement via optical means. Distortion measurement may be done by comparing scribed reference marks on the product glass with scribed reference marks on a precision scribed glass reference plate, before and after a glass shearing process. A measured difference between such scribe marks is relatable to a level of stress in the product glass. Manufacturers also might desire to measure glass warp, glass compaction, glass thickness, etc., for which relevant measurement devices are used, such as warp gauges, compaction gauges, thickness gauges, etc.
One such measurement apparatus is a distortion gauge, a goal of which is to measure increasingly larger display glass sizes. The prior maximum size of the display glass was 3.2 meters for the distortion gauge and related equipment. Among its various parts, a distortion gauge includes a granite base, a precision scribed glass reference plate on top of the granite base, and optical measurement equipment. In the past, a glass reference comprised of a single sheet of glass was used because of small glass product sizes that were being measured. To accommodate the desire for larger product glass sizes, larger single sheet glass reference plates are desired. However, reference glass and product glass of such larger sizes are difficult to process and handle due to their size, fragility, and sensitivity. Even minor damage to a portion of the reference plate glass may require replacement of the entire single sheet. Nevertheless, it would be desirable to have a suitable glass handling and processing systems and methods able to handle larger glass product sizes.
It would therefore be desirable to further improve the handling and processing technology applicable to the manufacture of larger product glass sheets, while minimizing the challenges and risks associated with such large product glass and glass reference plate sizes.